Replacement terminal for attachment to broken off end of electrical contact spring



Oct. 1965 P. D. KREBS ETAL 3,210,508

REPLACEMENT TERMINAL FOR ATTACHMENT To BROKEN OFF END OF ELECTRICAL CONTACT SPRING Filed Aug. 5, 1965 FIG. 3

INVENTORS.

7 PETER 0. KREBS BY CHARLES F. ZEBROWSKI ATTY.

United States Patent REPLACEMENT TERMTNAL F01 2 ATTACHMENT Til) BRGKEN OFF END OF ELEQ'LKWAL ZON- TACT SPRlNG Peter D. Krebs, Harwood Heights, and (Iharies 1F. Ze-

browski, (lineage, ilk, assign-tars tn Automatic Electric Laboratories, fine, Northlake, llliL, a corpuratinn ef Delaware Filed Aug. 5, 1963, Ser. No. 2%,793 ll Claim. (Cl. Edd-171) Our invention relates in general to a repair terminal for electrical contact springs and more specifically to a replacement terminal for repairing such contact springs when the terminal end has been broken off.

In present day practice electrical relay springs are provided with a long somewhat thin spike at the terminal end thereof, to which the end of a connecting wire is attached by a machine which winds the Wire around the spike terminal so tightly that good contact is obtained even without soldering. These contact springs are assembled in spring pileups on relays or in switches before the wires are attached thereto. At times the spike ends of the springs become broken off in handling or in attaching the wires thereto and in this case it has been necessary to dismantle the Whole spring pileup and replace the broken off spring before a wire could be attached thereto.

In order to obviate this difficulty we have provided a replacement terminal and method of applying it to the broken end of the spring while the spring is still assembled in its pileup. The replacement terminal is formed of hard tempered nickel silver or the like with a trifurcated end of which the two outer forks are formed as shown with downwardly eXtending projections or knife edges. The end of the spring from which the spike has been broken off is provided with a pair of notches by means of a hand cutting tool and the trifurcated end of the replacement terminal is then forced over such broken end until the knife edges of the two outer forks, snap into the notches in the end of the spring. The joint thus formed may then be further secured by applying a drop of solder to the point where the knife edges enter the notches.

Further features of our invention will be apparent from the following detailed description by reference to the accompanying drawings in which:

FIG. 1 illustrates one form of electrical relay having a spring pileup including a group of the type of springs to which our invention is applicable.

FIG. 2 illustrates a single spring as it appears before assembly in a relay.

FIG. 3 shows the manner in which the spike at the end of such a spring may be broken off and the notches which are cut into such broken end.

FIGS. 4 and 5 are enlarged top and side views respec tively showing the replacement terminal and the manner in which the trifurcated end thereof is formed to provide the knife edges to cooperate with the notches in the spring end.

FIG. 6 is a top view of a spring with the replacement terminal applied thereto.

FIG. 7 is a side view of the spring and terminal as seen in FIG. 6.

Referring now to the drawing we will describe in detail the replacement terminal shown therein and the method of applying the same to a spring from which the original terminal section has been broken.

In FIG. 2 we have shown one of the springs i with its original terminal end 2 still attached thereto and showing how a connecting wire 3 is wound around the terminal end to make contact therewith. In FIG. 1 we have shown how a number of such springs are assembled in a spring pileup on a relay of the telephone type. As previously stated, there are times when the connecting terminal 2 of one of the springs it may be broken off either in handling or in attaching a wire thereto. We have shown the spring l in FIG. 3 with the terminal end broken off along a line 4.

In order to eliminate the necessity of dismantling a whole spring pileup when one of the terminals is broken off, we have provided a replacement terminal 5, shown in FIGS. 4 and 5. This terminal has a trifurcated end with the two outer forks 6 and 7 bent upward from the third fork d and then curved downward and up at the end to form the knife edges 6a and 7a. It will be noted that the knife edges 6a and 7a lie in the same horizontal plane with the upper surface of the center fork 8.

In order to aid in securing the replacement terminal 5 to the broken end of spring 1 a pair of notches 9 and ill are cut through the edges of the broken off section of spring It as shown in PEG. 3. A long jawed punch or cutting tool is used to punch out these two notches 9 and it) or such notches may be formed in the springs originally so that they will be present in any spring which may be broken off.

Referring now to FIGS. 6 and 7 we have shown how the replacement terminal 5 is forced over the broken end of spring l. with the prongs 6 and 7 on one side of the spring and the center prong it on the opposite side. The terminal 5 is pressed over the broken end i until the knife edges 6a and 7a snap into the two notches 9 and id to hold the terminal in place. If desired, a drop of solder may be placed on the joint where the knife edges rest in slots or notches 9 and it) to further secure the replace ment terminal to the broken end of spring 1. This drop of solder would be placed on the upper side of the joint as seen in FIG. 7 so that it would flow over fork 8 and into notches 9 and it) into contact with knife edges 6a and 7:1 as they rest in the notches.

It will thus be seen that a new terminal end may easily be applied to the spring from which the original terminal end has been broken and that a connecting wire may then be wound on the spike 5 thereof to insure a proper connection with the spring.

Having fully described the various features and aspects of our invention what we consider to be novel and desire to have protected by Letters Patent will be pointed out in the appended claim.

What is claimed is:

The combination with an electrical spring of which the terminal end has been broken off and in which a pair of notches have been provided adjacent the broken off end of the spring, of a replacement terminal replacing the broken off end of the spring having a terminal spike at one end and having the other end furcated to form a series of prongs with certain of the prongs bent away from an other of the prongs to provide entry space for the broken end of the spring between said prongs, said replacement terminal forced over said broken end of the spring with 3 certain of said prongs on either side thereof, certain of said prongs bent in and out to form knife edges which snap into said pair of notches in the spring to rigidly hold the terminal in place on said broken off end of said spring to provide a spike terminal to which a Wire may be attached to make connections to said spring.

References Cited by the Examiner UNITED STATES PATENTS 1,869,566 8/32 Krahl 339-145 2,077,622 4/37 Field 200-171 2,285,657 6/42 Hickman 200-171 3/49 Fogg 29-401 12/51 Hayes 339-256 12/ 5 6 B atcheller 3 39-25 6 5/59 Narlock 29-401 4/60 Gellatly et a1 200-166 8/ 61 Anderson 3 39-25 6 FOREIGN PATENTS 7/ 5 1 Germany.

BERNARD A. GIIJHEANY, Primary Examiner.

WHITMORE A. WILTZ, Examiner. 

